Microelectronic devices, such as semiconductor devices, are generally fabricated on and/or in semiconductor material wafers. In wafer level packaging applications, a thick film of photoresist is applied to the wafer and patterned via photolithography. One or more metals are plated through the pattern in the photoresist, to form microelectronic components or interconnections. The photoresist film is then stripped or removed in a using a process liquid, such as a solvent, which chemically reacts with the photoresist film to remove the photoresist film off of the wafer.
Removing the photoresist can be difficult due to the thickness of the photoresist film. During the removing step, some of the photoresist film, which is typically about 50 to 250 microns thick, often comes off the wafer in relatively large gelatinous or diaphanous-like pieces, referred to here as solids, which are not fully dissolved by the process liquid. This results in a large volume of photoresist pieces accumulating in the process liquid, which can degrade the process liquid, clog filters or other fluid components and require frequent cleaning of the processing system. Engineering challenges remain in providing systems and methods for removing photoresist films.